Object with tear-shaped suspension for annular bodies

ABSTRACT

An object includes an annular outer body having an interior surface; and an annular inner body disposed inside the annular outer body, the annular inner body having an exterior surface defining an annular passage with the interior surface of the annular outer body. A plurality of suspension elements connects the interior surface of the annular outer body to the exterior surface of the annular inner body, each suspension element configured to substantially rigidly locate a position of the annular outer body relative to the annular inner body in axial and lateral directions while permitting controlled deflection in a radial direction. Each suspension element has an at least partially tear-shaped cross-section.

BACKGROUND OF THE INVENTION

The disclosure relates generally to manufacturing annular bodies, and more particularly, to an object with a tear-shaped suspension for annular bodies such as those used in fuel nozzles.

Annular bodies are used in a wide variety of industrial settings in which the bodies must be positioned relative to one another and withstand a range of environmental changes. One application in which such structures are employed are fuel nozzles such as those employed on gas turbines. In this setting, a number of generally concentric annular bodies create passages therebetween to deliver combustion materials such as fuel(s) and/or air to a combustion chamber. In order for the fuel nozzle to remain thermally compliant, i.e., maintain positioning, physical integrity, etc., an annular outer heat shield is oftentimes formed about the outermost annular body of the fuel nozzle. Typically, the fuel nozzle annular bodies are configured to be stiff axially relative to a centerline thereof, but radially pliant.

BRIEF DESCRIPTION OF THE INVENTION

A first aspect of the disclosure provides an object, comprising: an annular outer body having an interior surface; an annular inner body disposed inside the annular outer body, the inner body having an exterior surface defining an annular passage with the interior surface of the annular outer body; and a plurality of suspension elements connecting the interior surface of the annular outer body to the exterior surface of the inner body, each suspension element configured to substantially rigidly locate a position of the annular outer body relative to the inner body in axial and lateral directions while permitting controlled deflection in a radial direction, and wherein each suspension element has an at least partially tear-shaped cross-section.

A second aspect of the disclosure provides a fuel nozzle, comprising: an annular outer heat shield having an interior surface; an annular inner body disposed inside the outer heat shield, the inner body having an interior for delivering a combustion material and an exterior surface defining an annular passage with the interior surface of the outer heat shield; and a plurality of suspension elements connecting the interior surface of the outer heat shield to the exterior surface of the inner body, each suspension element configured to substantially rigidly locate a position of the outer heat shield relative to the inner body in axial and lateral directions while permitting controlled deflection in a radial direction, and wherein each suspension element has an at least partially tear-shaped cross-section.

A third aspect of the disclosure provides a non-transitory computer readable storage medium storing code representative of an object, the object physically generated upon execution of the code by a computerized additive manufacturing system, the code comprising: code representing the object, the object including: an annular outer body having an interior surface; an annular inner body disposed inside the annular outer body, the inner body having an exterior surface defining an annular passage with the interior surface of the annular outer body; and a plurality of suspension elements connecting the interior surface of the annular outer body to the exterior surface of the inner body, each suspension element configured to substantially rigidly locate a position of the annular outer body relative to the inner body in axial and lateral directions while permitting controlled deflection in a radial direction, and wherein each suspension element has an at least partially tear-shaped cross-section.

The illustrative aspects of the present disclosure are designed to solve the problems herein described and/or other problems not discussed.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of this disclosure will be more readily understood from the following detailed description of the various aspects of the disclosure taken in conjunction with the accompanying drawings that depict various embodiments of the disclosure, in which:

FIG. 1 shows a block diagram of an additive manufacturing process including a non-transitory computer readable storage medium storing code representative of an object according to embodiments of the disclosure.

FIG. 2 shows a perspective view of an illustrative object including a suspension elements, according to embodiments of the disclosure.

FIG. 3 shows a cross-sectional view of the illustrative object of FIG. 2 along line 3-3.

FIG. 4 shows an enlarged cross-sectional view of the object of FIG. 3.

FIG. 5 shows a perspective view of an end of an object including suspension elements, in accordance with embodiments of the disclosure.

FIG. 6 shows an end view of an object including suspension elements, in accordance with embodiments of the disclosure.

FIG. 7 shows a cross-sectional view of one illustrative suspension element including an at least partially airfoil cross-section, according to embodiments of the disclosure.

It is noted that the drawings of the disclosure are not to scale. The drawings are intended to depict only typical aspects of the disclosure, and therefore should not be considered as limiting the scope of the disclosure. In the drawings, like numbering represents like elements between the drawings.

DETAILED DESCRIPTION OF THE INVENTION

As an initial matter, in order to clearly describe the current disclosure it will become necessary to select certain terminology when referring to and describing relevant machine components within an object, illustrated as a fuel nozzle herein. When doing this, if possible, common industry terminology will be used and employed in a manner consistent with its accepted meaning. Unless otherwise stated, such terminology should be given a broad interpretation consistent with the context of the present application and the scope of the appended claims. Those of ordinary skill in the art will appreciate that often a particular component may be referred to using several different or overlapping terms. What may be described herein as being a single part may include and be referenced in another context as consisting of multiple components. Alternatively, what may be described herein as including multiple components may be referred to elsewhere as a single part.

In addition, several descriptive terms may be used regularly herein, and it should prove helpful to define these terms at the onset of this section. These terms and their definitions, unless stated otherwise, are as follows. As used herein, “downstream” and “upstream” are terms that indicate a direction relative to the flow of a fluid, such as the working fluid through the fuel. The term “downstream” corresponds to the direction of flow of the fluid, and the term “upstream” refers to the direction opposite to the flow. The terms “forward” and “aft,” without any further specificity, refer to directions, with “forward” referring to the front or fluid receiving end of the fuel nozzle, and “aft” referring to the rearward or discharge end of the fuel nozzle. It is often required to describe parts that are at differing radial positions with regard to a centerline or center axis. The term “radial” refers to movement or position perpendicular to an axis. In cases such as this, if a first component resides closer to the axis than a second component, it will be stated herein that the first component is “radially inward” or “inboard” of the second component. If, on the other hand, the first component resides further from the axis than the second component, it may be stated herein that the first component is “radially outward” or “outboard” of the second component. The term “axial” refers to movement or position parallel to the centerline or axis. Finally, the term “circumferential” refers to movement or position around the centerline or axis. It will be appreciated that such terms may be applied in relation to the centerline of the fuel nozzle.

As indicated above, the disclosure provides an object including suspension elements for positioning annular bodies relative to one another, e.g., concentrically. A method for manufacturing a metallic object is also described. In one example, the object may take the form of fuel nozzle such as those used for gas turbines, and may be formed using additive manufacturing.

To illustrate an example of an additive manufacturing process, FIG. 1 shows a schematic/block view of an illustrative computerized additive manufacturing (AM) system 100 for generating an object 102. In this example, system 100 is arranged for DMLM, a metal powder additive manufacturing process. It is understood that the general teachings of the disclosure are equally applicable to other forms of additive manufacturing. Object 102 is illustrated as a fuel nozzle 103 including, as will be described, a number of annular bodies 150A-D (FIG. 3); however, it is understood that the additive manufacturing process can be readily adapted to manufacture any object including spaced, annular bodies. AM system 100 generally includes a computerized AM control system 104 and an AM printer 106. AM system 100, as will be described, executes code 120 that includes a set of computer-executable instructions defining object 102 to physically generate the object using AM printer 106. Each AM process may use different raw materials in the form of, for example, fine-grain metal powder, a stock of which may be held in a chamber 110 of AM printer 106. In the instant case, object 102 may be made of metal or a metal alloy. As illustrated, an applicator 112 may create a thin layer of raw material 114 spread out as the blank canvas from which each successive slice of the final object will be created. In the example shown, a laser or electron beam 116 fuses particles for each slice, as defined by code 120. Various parts of AM printer 106 may move to accommodate the addition of each new layer, e.g., a build platform 118 may lower and/or chamber 110 and/or applicator 112 may rise after each layer.

AM control system 104 is shown implemented on computer 130 as computer program code. To this extent, computer 130 is shown including a memory 132, a processor 134, an input/output (I/O) interface 136, and a bus 138. Further, computer 130 is shown in communication with an external I/O device/resource 140 and a storage system 142. In general, processor 134 executes computer program code, such as AM control system 104, that is stored in memory 132 and/or storage system 142 under instructions from code 120 representative of object 102. While executing computer program code, processor 134 can read and/or write data to/from memory 132, storage system 142, I/O device 140 and/or AM printer 106. Bus 138 provides a communication link between each of the objects in computer 130, and I/O device 140 can comprise any device that enables a user to interact with computer 130 (e.g., keyboard, pointing device, display, etc.). Computer 130 is only representative of various possible combinations of hardware and software. For example, processor 134 may comprise a single processing unit, or be distributed across one or more processing units in one or more locations, e.g., on a client and server. Similarly, memory 132 and/or storage system 142 may reside at one or more physical locations. Memory 132 and/or storage system 142 can comprise any combination of various types of non-transitory computer readable storage medium including magnetic media, optical media, random access memory (RAM), read only memory (ROM), etc. Computer 130 can comprise any type of computing device such as a network server, a desktop computer, a laptop, a handheld device, a mobile phone, a pager, a personal data assistant, etc.

Additive manufacturing processes begin with a non-transitory computer readable storage medium (e.g., memory 132, storage system 142, etc.) storing code 120 representative of object 102. As noted, code 120 includes a set of computer-executable instructions defining object 102 that can be used to physically generate the object, upon execution of the code by system 100. For example, code 120 may include a precisely defined 3D model of object 102 and can be generated from any of a large variety of well-known computer aided design (CAD) software systems such as AutoCAD®, TurboCAD®, DesignCAD 3D Max, etc. In this regard, code 120 can take any now known or later developed file format. For example, code 120 may be in the Standard Tessellation Language (STL) which was created for stereolithography CAD programs of 3D Systems, or an additive manufacturing file (AMF), which is an American Society of Mechanical Engineers (ASME) standard that is an extensible markup-language (XML) based format designed to allow any CAD software to describe the shape and composition of any three-dimensional object to be fabricated on any AM printer. Code 120 may be translated between different formats, converted into a set of data signals and transmitted, received as a set of data signals and converted to code, stored, etc., as necessary. Code 120 may be an input to system 100 and may come from a part designer, an intellectual property (IP) provider, a design company, the operator or owner of system 100, or from other sources. In any event, AM control system 104 executes code 120, dividing object 102 into a series of thin slices that it assembles using AM printer 106 in successive layers of powder. In the DMLM example, each layer is melted or sintered to the exact geometry defined by code 120 and fused to the preceding layer. Subsequently, object 102 may be exposed to any variety of finishing processes, e.g., minor machining, sealing, polishing, assembly to another part, etc.

FIGS. 2-3 show object 102 including annular bodies 150A, 150B (FIG. 3) capable of employing a plurality of suspension elements 160 (FIG. 3) according to the teachings of the disclosure. FIG. 2 shows a perspective view, and FIG. 3 shows a cross-sectional view of object 102 along line 3-3 in FIG. 2. Object 102 is illustrated in the form of fuel nozzle 103. It is emphasized that object 102 in the form of fuel nozzle 103 is merely illustrative of an object including annular bodies 150 requiring a plurality of suspension elements 160, and the teachings of the disclosure can be applied to any object similarly structured. Object 102 (fuel nozzle 103) can be manufactured using additive manufacturing such as a metal power additive manufacturing system 100 (FIG. 1) or other additive manufacturing system, depending on material used.

With reference to FIGS. 3-6, details of embodiments of object 102 will be described. FIG. 4 shows an enlarged cross-sectional view, FIG. 5 shows a perspective view and FIG. 6 shows an end view of object 102 (FIGS. 5 and 6 from a proximal end of fuel nozzle 103). Object 102 may include an annular outer body 150A having an interior surface 162, and an annular inner body 150B disposed inside annular outer body 150A. Inner body 150B has an exterior surface 164 defining an annular passage 154A with interior surface 162 of annular outer body 150A. Where object 102 is a fuel nozzle 103, it may also include additional annular bodies 150C, D (4 total shown, 150A-D) that extend to deliver their respective fluids, e.g., air or fuel, to or near an end 152 (FIG. 2) of fuel nozzle 103. Generally, each annular body 150B-D, including annular outer body 150A, extends parallel to a centerline axis C, i.e., with some variations. Annular bodies 150B-D create concentric or near concentric annular passages 154B-D for fuel and air. In the example shown, annular inner body 150B may include an outer, combustible fuel carrying element 166 (FIG. 4) of fuel nozzle 103, i.e., an outer element of the parts of fuel nozzle 103 that carry fuel or air for combustion outside of fuel nozzle 103. Here, annular outer body 150A may take the form of a heat shield 168 for the rest of fuel nozzle 103. In this setting, a space between interior surface 162 of annular outer body 150A and exterior surface 164 of annular inner body 150B provides an annular passage 154A for carrying a coolant 170, e.g., air, to cool fuel nozzle 103. Coolant 170 may not be used in the combustion process occurring near end 152 (FIG. 2).

In accordance with embodiment of the disclosure, a plurality of suspension elements 160 connect interior surface 162 of annular outer body 150A to exterior surface 164 of annular inner body 150B. Each suspension element 160 is configured to substantially rigidly locate a position of annular outer body 150A relative to annular inner body 150B in axial (along centerline C) and lateral (circumferentially about centerline C) directions while permitting controlled deflection in a radial direction (perpendicular to centerline C). To this end, as shown in FIGS. 5 and 6, each suspension element 160 may include a first end 180 coupled to annular inner body 150B and a circumferentially spaced, second end 182 coupled to annular outer body 150A. As shown in FIG. 4, each suspension element 160 extends a distance D parallel to centerline axis C to create a structure capable of resisting axial and lateral movement. Further, as shown in FIGS. 5 and 6, first end 180 may couple to annular inner body 150B at a first angle α1 between 85° and 95° (e.g., 90°), and second end 182 couples to annular outer body 150A at a second angle α2 between 85° and 95° (e.g., 90°). In this fashion, each suspension element 160 may have an S-shape viewed in the direction of the centerline axis C (see FIG. 6). Any number of suspension elements 160 deemed necessary to provide the desired, limited movement may be employed. In FIGS. 5 and 6, seven (7) elements 160 are employed.

In embodiments of the disclosure, suspension elements 160 may be circumferentially spaced within annular passage 154A. That is, plurality of suspension elements 160 may be circumferentially spaced between interior surface 162 of annular outer body 150A and exterior surface 164 of annular inner body 150B. In this fashion, suspension elements 160 provide even absorption of stresses. It is understood that elements 160 may be unevenly spaced, e.g., if other mounting structure couples to annular outer body 150A, to provide an imbalanced suspension capable of addressing an imbalanced loading. In one embodiment, first end 180 of each respective suspension element 160 may be within 5° (angle β) of a circumferentially spaced, second end 182 of an adjacent suspension element 162 as measured relative to centerline C. The circumferential arc (CA) (FIG. 6), i.e., the amount each element 160 extends arcuately about centerline C, may vary depending on the number of elements 160 employed and the desired spacing, if any, between adjacent ends 180, 182 of adjacent suspension elements 160.

In order to reduce a pressure drop of coolant 170 within annular passage 154A, as shown best in FIGS. 3, 4 and 5, each suspension element 160 has an at least partially tear-shaped cross-section. In one embodiment, the tear-shape may be airfoil-shaped. As shown in a cross-section of a suspension element 160 in FIG. 7, the at least partially airfoil-shape can take the form of any desired airfoil such as but not limited to those promulgated by the National Advisory Committee for Aeronautics (NACA). The tear-shaped cross-section may include a leading edge 184 facing a direction of flow of coolant 170 (See FIG. 4).

A fuel nozzle 103 in accordance with embodiments of the disclosure may include annular outer heat shield 150A having interior surface 162. Annular inner body 150B may be disposed inside outer heat shield 150A. Inner body 150B has an interior 154B for delivering a combustion material, e.g., fuel and/or air, and exterior surface 164 defining an annular passage 154A with interior surface 162 of outer heat shield 150A. Plurality of suspension elements 160 connect interior surface 162 of outer heat shield 150A to exterior surface 164 of inner body 150B. Each suspension element 160 is configured to substantially rigidly locate a position of outer heat shield 150A relative to inner body 150B in axial and lateral directions while permitting controlled deflection in a radial direction. As noted, each suspension element 160 may include an at least partially tear-shaped cross-section.

As noted, object 102 and fuel nozzle 103 may be formed using the AM processes described herein, providing a one-piece construction that is tolerant to thermally induced radial growth and relatively large axial forces, but also provides a low pressure drop for coolant. The teachings of the disclosure are applicable to any situation in which annular bodies need to be positioned within one another, and limited movement caused by, for example, thermal stress, is required.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. “Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about,” “approximately” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be combined and/or interchanged, such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. “Approximately” as applied to a particular value of a range applies to both values, and unless otherwise dependent on the precision of the instrument measuring the value, may indicate +/−10% of the stated value(s).

The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiment was chosen and described in order to best explain the principles of the disclosure and the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated. 

What is claimed is:
 1. An object, comprising: an annular outer body having an interior surface; an annular inner body disposed inside the annular outer body, the annular inner body having an exterior surface defining an annular passage with the interior surface of the annular outer body; and a plurality of suspension elements connecting the interior surface of the annular outer body to the exterior surface of the annular inner body, each suspension element configured to substantially rigidly locate a position of the annular outer body relative to the annular inner body in axial and lateral directions while permitting controlled deflection in a radial direction, and wherein each suspension element has an at least partially tear-shaped cross-section.
 2. The object of claim 1, wherein each suspension element includes a first end coupled to the annular inner body and a circumferentially spaced, second end coupled to the annular outer body.
 3. The object of claim 2, wherein the first end couples to the annular inner body at a first angle between 85° and 95°, and the second end couples to the annular outer body at a second angle between 85° and 95°.
 4. The object of claim 2, wherein the annular outer body extends parallel to a centerline axis and each suspension element has an S-shape viewed in the direction of the centerline axis.
 5. The object of claim 4, wherein each suspension element extends a distance parallel to the centerline axis.
 6. The object of claim 4, wherein the first end of each respective suspension element is within 5° of the circumferentially spaced, second end of an adjacent suspension element as measured relative to the centerline.
 7. The object of claim 1, wherein the plurality of suspension elements are circumferentially spaced between the interior surface of the annular outer body and the exterior surface of the annular inner body.
 8. The object of claim 1, wherein the annular inner body includes an outer, combustible fuel carrying element of a fuel nozzle, and the annular outer body includes a heat shield for the fuel nozzle, and wherein a space between the interior surface of the annular outer body and the exterior surface of the annular inner body carries a coolant therethrough.
 9. A fuel nozzle, comprising: an annular outer heat shield having an interior surface; an annular inner body disposed inside the annular outer heat shield, the annular inner body having an interior for delivering a combustion material and an exterior surface defining an annular passage with the interior surface of the outer heat shield; and a plurality of suspension elements connecting the interior surface of the outer heat shield to the exterior surface of the annular inner body, each suspension element configured to substantially rigidly locate a position of the outer heat shield relative to the annular inner body in axial and lateral directions while permitting controlled deflection in a radial direction, and wherein each suspension element has an at least partially tear-shaped cross-section.
 10. The fuel nozzle of claim 9, wherein each suspension element includes a first end coupled to the annular inner body and a circumferentially spaced, second end coupled to the outer heat shield.
 11. The fuel nozzle of claim 10, wherein the first end couples to the annular inner body at a first angle between 85° and 95°, and the second end couples to the outer heat shield at a second angle between 85° and 95°.
 12. The fuel nozzle of claim 10, wherein the outer heat shield extends parallel to a centerline axis and each suspension element has an S-shape viewed in the direction of the centerline axis.
 13. The fuel nozzle of claim 12, wherein each suspension element extends a distance parallel to the centerline axis.
 14. The fuel nozzle of claim 12, wherein the first end of each respective suspension element is within 5° of the circumferentially spaced, second end of an adjacent suspension element measured relative to the centerline.
 15. The fuel nozzle of claim 9, wherein the plurality of suspension elements are circumferentially spaced between the interior surface of the outer heat shield and the exterior surface of the annular inner body.
 16. The fuel nozzle of claim 9, wherein a space between the interior surface of the outer heat shield and the exterior surface of the annular inner body carries a coolant therethrough.
 17. The fuel nozzle of claim 16, wherein the at least partially tear-shaped cross-section includes a leading edge facing a direction of flow of the coolant.
 18. A non-transitory computer readable storage medium storing code representative of an object, the object physically generated upon execution of the code by a computerized additive manufacturing system, the code comprising: code representing the object, the object including: an annular outer body having an interior surface; an annular inner body disposed inside the annular outer body, the annular inner body having an exterior surface defining an annular passage with the interior surface of the annular outer body; and a plurality of suspension elements connecting the interior surface of the annular outer body to the exterior surface of the annular inner body, each suspension element configured to substantially rigidly locate a position of the annular outer body relative to the annular inner body in axial and lateral directions while permitting controlled deflection in a radial direction, wherein each suspension element has an at least partially tear-shaped cross-section.
 19. The storage medium of claim 18, wherein each suspension element includes a first end coupled to the annular inner body and a circumferentially spaced, second end coupled to the annular outer body.
 20. The storage medium of claim 18, wherein each suspension element extends a distance parallel to the centerline axis. 